threatened plants

Adult mortality, seed production, and seedling establishment of two species of New Zealand broom (Carmichaelia juncea and C. vexillata) were studied in exclosure trials to determine the level of threat posed by herbivory by introduced mammals. While no effect on mortality was observed for either species, herbivory by hares drastically reduced seed production and subsequent seedling establishment in C. juncea. C. vexillata seemed less vulnerable to herbivore damage due to its plant architecture, as well as the timing and intensity of the herbivore impact.

Dactylanthus taylorii, a root parasite in the family Balanophoraceae, is New Zealand's only fully parasitic flowering plant. It grows attached to the roots of a wide range of hardwood trees and shrubs, often in fire-induced secondary forest on the margin of podocarp-hardwood forest. It is inconstantly dioecious with a skewed sex ratio of approximately 5:1 male to female inflorescences. The inflorescences, especially the males, contain a large quantity of nectar, up to 1.6 mi, and can produce 0.5 mi per day for 10 days.

Tiritiri Matangi Island (‘Tiri’) in the Hauraki Gulf of the northern North Island of New Zealand was deforested, pastorally farmed, and then farming was abandoned in 1972. This history is typical of many northern New Zealand islands. The island’s modern history is less typical; since 1984 it has been the focus of a major restoration project involving thousands of volunteers. No original forest remains, but grazed secondary forest in a few valley bottoms covered about 20% of the island when farming was abandoned. Tiri’s wild vascular flora was recorded in the 1900s and again in the 1970s.